Hydrocarbons, such as oil and gas, are commonly obtained from subterranean formations that may be located onshore or offshore. The development of subterranean operations and the processes involved in removing hydrocarbons from a subterranean formation typically involve a number of different steps such as, for example, drilling a wellbore at a desired well site, treating the wellbore to optimize production of hydrocarbons, and performing the necessary steps to produce and process the hydrocarbons from the subterranean formation.
After drilling a wellbore that intersects a subterranean hydrocarbon-bearing formation, a variety of wellbore tools may be positioned in the wellbore during completion, production, or remedial activities. It is common practice in completing oil and gas wells to set a string of pipe, known as casing, in the well to isolate the various formations penetrated by the well from the wellbore. The casing is typically perforated opposite the formation to provide flowpaths for the valuable fluids from the formation to the wellbore. If production tubing is simply lowered into the wellbore and fluids are allowed to flow directly from the formation, into the wellbore, and through the production tubing to the earth's surface, fine sand from the formation could be swept along with the fluids and carried to the surface by the fluids.
Gravel pack operations are typically performed in subterranean wells to prevent fine particles of sand or other debris from being produced along with valuable fluids extracted from the formation. If produced (i.e., brought to the earth's surface), the fine sand tends to erode production equipment, clog filters, and present disposal problems. Conventional gravel pack operations prevent the fine sand from being swept into the production tubing by installing a sand screen on the end of the production tubing. The wellbore in an annular area between the screen and the casing is then filled with a relatively large grain sand or ceramic proppant (i.e., “gravel”). The gravel prevents the fine sand from packing off around the production tubing and screen, and the screen prevents the large grain sand from entering the production tubing.
Gravel pack systems generally include a packer that is set to seal and anchor the gravel pack system, and the production tubing, in place within the perforated wellbore. Currently, workstring tubing is plugged below the packer and pressure applied to the tubing to set the packer. The tubing is raised afterward to position the tubing for gravel pack pumping operations. Unfortunately, this raising of the gravel pack system while the tubing is plugged can lead to a pressure differential between components above and below the packer. This pressure differential can pull parts of the formation inward toward the wellbore, leading to bridging off or collapse of the formation around the screen of the gravel pack system.